Various types of prosthetic leg accessories are known in the prior art. However, what has been needed is a securing apparatus for a prosthetic leg including a belt strap, a pair of hook and loop fasteners disposed on the belt strap, and a pair of top attachment loops attached to the belt strap. What has been further needed is a sled-shaped support attachment that includes a flattened base portion, a pair of support extensions, and a pair of bottom attachment loops. Lastly, what has been needed is for each of a right ratchet strap and a left ratchet strap of a pair of ratchet straps to have an upper spring-loaded clip and a lower spring-loaded clip. The upper spring-loaded clip of each of the right ratchet strap and the left ratchet strap is attachable to the right top attachment loop and the left top attachment loop, respectively. The lower spring-loaded clip of each of the right ratchet strap and the left ratchet strap is attachable to a right bottom attachment loop and a left bottom attachment loop, respectively, of the support attachment. The support attachment selectively supports a foot portion of a prosthetic leg between the pair of support extensions when the pair of ratchet straps has attached the support attachment to the belt strap. The securing apparatus for a prosthetic leg thus provides additional securement to a user's prosthetic leg while the user is engaged in any type of particularly extreme activity including, but not limited to, riding amusement park rides and sky diving.